Skip to content
WanderNerd
Check a flight

Flight Reliability

DL 623 · Delta Air Lines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and DL 623 moved between routes during this period. Numbers below combine all of them, so treat them as background, not a verdict. For a cleaner answer, check the route you are actually flying.

Combined across all its routes

73%
Arrive within 15 minutes
8 min
Average arrival delay
4.2%
Cancelled
7 min early
Median arrival delay

Based on 264 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon56%(39 flights)
  • Tue74%(42 flights)
  • Wed88%(40 flights)
  • Thu75%(36 flights)
  • Fri77%(31 flights)
  • Sat75%(28 flights)
  • Sun67%(36 flights)
On-time by departure window
  • 6–9 AM—(2 flights)
  • 9 AM–12 PM93%(76 flights)
  • 6–9 PM64%(174 flights)
On-time trend by month
93%
May

Jun 66% → May 93% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202566%29
July 202570%30
August 202570%27
September 202582%27
October 202563%27
November 202555%22
December 202533%15
January 2026100%12
February 2026100%12
April 202685%20
May 202693%28
Departures on time
66%
Diverted
0.4%
Flights flown
252
Months covered
12

Keep nerding

Based on 264 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.